Fig. 4

Ratio between the estimated and actual plasma frequencies in the reflection point. In panel a, red, blue, and green dots correspond to the estimation using Eq. (6), Eq. (3), and Eq. (7), respectively. Distance to the reflection point is shown on the horizontal axes. In panel b, dots show the relationship between the frequency ratio estimated by Eq. (6) and the slant range ratio. Green/black dots correspond to distances shorter/longer than 1200 km. In panel c, gray dots correspond to the estimation using Eq. (8). Green dots show the ratio between estimated plasma frequency using Eq. (8) and the actual critical frequency of the F2 layer. Distance to the reflection point is shown on the horizontal axes. Dashed lines show linear regressions